(p. 7) By the European Middle Ages, craftiness manifested itself most significantly in a new use of energy. An efficient horse collar had disseminated throughout society, drastically increasing farm acreage, while water mills and windmills were improved, increasing the flow of lumber and flour and improving drainage. And all this plentitude came without slavery. As Lynn White, historian of technology, wrote, “The chief glory (p. 8) of the later Middle Ages was not its cathedrals or its epics or its scholasticism: it was the building for the first time in history of a complex civilization which rested not on the backs of sweating slaves or coolies but primarily on non-human power.” Machines were becoming our coolies.
Kelly, Kevin. What Technology Wants. New York: Viking Adult, 2010.